Officials of an Iranian opposition group have unveiled what they say is new evidence the Tehran government is trying to develop nuclear weapons.

A spokesman for the National Council of Resistance of Iran told reporters in Washington Tehran is trying to hide two new facilities that are part of the government's alleged attempts to build a nuclear bomb.

Alireza Jafarzadeh says Iran's Defense Industry Organization has built a uranium enrichment facility called "Kolahdouz," which is located about 14 kilometers west of Tehran.

Mr. Jafarzadeh says the plant is hidden in a large, military complex where centrifuge equipment can operate as part of a pilot project for an enrichment plant in the city of Natanz.

"This will eventually act as a supplement to the uranium enrichment site in Natanz. In other words, this is the pilot facility where the uranium enrichment will take place," he said. "It will be perfected and the experience used for this will be used for their bigger, ultimate, uranium enrichment facility in Natanz."

Mr. Jafarzadeh says a new facility under construction is the Ardekan Nuclear Fuel Site and is located in the central part of the country.

He says this plant is designed to treat uranium and will be completed in about two years.

Mr. Jafarzadeh says the two plants show that Iran is moving forward quickly to gain access to nuclear weapons.

"The whole purpose behind such an ambitious nuclear weapons program obviously is to gain the upper hand in the region, to create fear and terror and to pave the way for their long-standing ambition of reviving the Ottoman Empire and expanding the very evil rule of the clerics in the region," he said.

While Iran says it is obtaining nuclear technology to generate electricity, U.S. officials argue the country has vast oil and gas reserves and does not need nuclear energy.

The National Council of Resistance of Iran has, in the past, revealed other sites it says are part of an ambitious effort by the Tehran government to build nuclear weapons.

The organization is the political wing of the People's Mujahedeen.

The People's Mujahedeen is on a State Department list of terrorist organizations, but is supported by some members of the U.S. Congress as a legitimate Iranian opposition group.